A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 767-200 and 767-300 series airplanes was published in the Federal Register on December 11, 2002 (67 FR 76120). That action proposed to require modification of the installation of the aft pressure bulkhead-to-floor insulation blankets. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nRequest To Change Compliance Time \n\n\tTwo commenters ask that the compliance time for the modification specified in the proposed AD be changed, as follows. \n\n\tThe first commenter asks that the compliance time be changed from 60 months to 84 months and states that the compliance times in the referenced service bulletin and the proposed AD are different. The commenter notes that the service bulletin specifies doing the modification during the next heavy maintenance check when the aft galleys are removed, and that such checks are done every 6 years. However, the proposed AD specifies doing the modification within 5 years after the effective date of the final rule. The commenter adds that the galleys on its airplanes are removed every 10 years for galley restoration and to facilitate structural inspections, per Maintenance Planning Document (MPD) Task CP53-200-04I. This task requires an initial inspection of the floor support structure under the galleys at 10 years, and at 5-year intervals after the initial inspection. The commenter states that the galleys are not removed every 6 years as called out in the "Clarification of Compliance Time" paragraph in the proposed AD. \n\n\tThe second commenter asks that the compliance time be changed from 60 months to 72 months and states that it requires a 72-month compliance time for doing the modification. The commenter adds thatthe effectivity in the referenced service bulletin was specifically revised to read "* * * the next heavy maintenance check when aft galleys are removed." The commenter notes that a 60-month compliance time will require it to schedule airplanes outside of regularly scheduled maintenance checks, or do the modification at an earlier check at considerable cost to the airline. \n\n\tWe agree with the commenters. We find that the commenters provided sufficient justification for extending the compliance time for modifying the installation of the aft pressure bulkhead-to-floor insulation blankets. The commenters also provided data to show that the majority of affected operators do the heavy maintenance check of the aft galleys at intervals that exceed the proposed 60-month compliance time. Thus, we have determined that the modification may be deferred until 7 years (84 months) after the effective date of this AD without jeopardizing the continued safety of the airplane fleet. The compliance time specified in paragraph (a) of this final rule has been changed accordingly. \n\nRequest To Change a Certain Section in Preamble \n\n\tOne commenter asks that the section in the preamble of the proposed AD titled "Clarification of Compliance Time" be changed to state that the heavy maintenance checks are done every 10 years, and that the modification should be done within 7 years after the effective date of the AD. \n\n\tAlthough we acknowledge and agree with the commenter's remarks on the section in the preamble of the proposed \n\nAD titled "Clarification of Compliance Time," that section is not restated in this final rule. Therefore, no change to the final rule is necessary in this regard. \n\nRequest To Exclude Freighter Airplanes From Applicability \n\n\tTwo commenters ask that the applicability in the proposed AD be changed to exclude Model 767 freighter airplanes, as follows. \n\n\tThe first commenter states that the effectivity in the referenced service bulletin applies only toModel 767 passenger airplanes, and notes that freighter airplanes are not affected. The commenter adds that the word "passenger" should be added to the Discussion section of the proposed AD. The commenter also asks that the Cost Impact section be changed to remove the freighter airplanes from the total number of U.S.-registered aircraft, which would reduce the cost impact for U.S. operators. \n\n\tThe second commenter states that the information in the applicability section of the proposed AD contradicts the effectivity specified in the referenced service bulletin, and should be clarified. The commenter notes that the applicability in the proposed AD specifies Model 767-200 and -300 series airplanes, certificated in any category; however, the effectivity in the service bulletin specifies Model 767- 200 and -300 passenger airplanes only. \n\n\tBoth commenters state that the Model 767 freighter airplane has different venting and decompression characteristics than the passenger airplane. The commenters add that the difference is in the location of the aft galley in the passenger airplane, which causes the airflow between the floor and the aft bulkhead to be different from that in freighter airplanes. \n\n\tWe agree with the commenters that the applicability section should be clarified; however, not in the manner proposed. Per the Model 767 Type Certificate Data Sheet, which specifies Model 767-200, -300, and - 300F series airplanes, the proposed AD clearly does not include Model 767-300F (freighter) airplanes in the applicability. \n\n\tHowever, as the line numbers are listed and have confused some operators, we have clarified the applicability in this final rule to specify "Model 767-200 and -300 series airplanes as listed in Boeing Service Bulletin 767-25A0300, Revision 1, dated May 2, 2002. * * *" In addition, we have removed the freighter airplanes from the total number of U.S.-registered aircraft in the Cost Impact section. However, although we acknowledge and agree with the first commenter's remarks on the Discussion section of the proposed AD, that section is not restated in this final rule. Therefore, no change to the final rule is necessary in that regard. \n\nNew Part Numbers \n\n\tOne commenter states that the manufacturer has not created new part numbers for all of the affected insulation blankets and is still shipping parts in the old configuration that preceeded the new configuration specified in the referenced service bulletin. \n\n\tAlthough we acknowledge the commenter's concern, we do not agree. Figure 1 (Insulation Blanket Modification) of Boeing Service Bulletin 767-25A0300, Revision 1, specifies that the insulation blankets are to be re-marked with new part numbers. No change to the final rule is necessary in this regard. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 739 airplanes of the affected design in the worldwide fleet. The FAA estimates that 296 airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the modification, and that the average labor rate is $60 per work hour. Required parts will cost approximately $397 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $170,792, or $577 per airplane. \n\tThe cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary toperform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n2. Section 39.13 is amended by adding the following new airworthiness directive: